[GRASS-dev] Re: [GRASS GIS] #308: Compiler error while building python swig

[GRASS GIS]

#308: Compiler error while building python swig
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  Reporter:  cgsbob               |       Owner:  grass-dev at lists.osgeo.org
      Type:  defect               |      Status:  new                      
  Priority:  major                |   Milestone:  6.4.0                    
 Component:  SWIG (all bindings)  |     Version:  svn-develbranch6         
Resolution:                       |    Keywords:  python swig              
  Platform:  Unspecified          |         Cpu:  Unspecified              
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Comment (by glynn):

 Replying to [comment:11 hamish]:
 > I checked in some fixes to devbr6 SVN but it still doesn't build.
 >
 {{{
 > python_grass6_wrap.c: In function '_wrap_Cluster_nbands_set':
 > python_grass6_wrap.c:48044: error: dereferencing pointer to incomplete
 type
 }}}

 The cluster stuff was moved into a separate library (lib/cluster and
 cluster.h). The imagery.i file still contains a definition for "struct
 Cluster", but the C++ code is assuming that imagery.h will provide a
 definition. The quick fix is to #include cluster.h.

 > Auto-generation of gis.i seems to be an important thing, so wrt to
 tackling that next:
 >
 >  - gis.i seems to be based on gis.h circa 12/17/04 (r16393)
 >
 > After removing comments and trailing whitespace, then diff'ing versus
 gis.h r16393 the changes between gis.h and gis.i are as follows:
 >
 {{{
 > -extern CELL CELL_NODATA;
 > +/*extern CELL CELL_NODATA; Sajith */
 }}}

 This appears to be unused.

 {{{
 > -    struct _Color_Rule_ *next;
 > -    struct _Color_Rule_ *prev;
 > +/*    struct _Color_Rule_ *next;
 > +    struct _Color_Rule_ *prev;  Commented By sajith I am confued
 here....*/
 }}}

 Can SWIG not handle recursive type declarations?

 > The duplication of the high,low structs was done by Sajith AFAICT.

 Can SWIG not handle multiple fields with the same anonymous structure
 type? If not, just add a named declaration for the structure before the
 "struct _Color_Rule_" declaration.

 > I've no idea why of course, but that's what it is.

 First, I suggest replacing the contents of gis.i with "%include
 <grass/gis.h>" and seeing if that actually causes any errors. Ditto for
 all of the other interfaces/*.i files.

 Essentially, SWIG aims to support the use of C/C++ header files directly.
 Although there is still some "not yet supported" syntax, the amount of it
 has decreased significantly since the early versions.

-- 
Ticket URL: <http://trac.osgeo.org/grass/ticket/308#comment:13>
GRASS GIS <http://grass.osgeo.org>